Die casting machine



Sept. 14, 1948. w. COULTHARD 2,449,280

DIE CASTING MACHINE Filed June 19, 1946 2 Sheets-Sheet 1 I8 I n vent 0r 6%7/247/5 daaZz /zald Atlorney p 1948' w. COULTHARD 2,449,280

DIE CASTING MACHINE a Sheets-Shed. 2

Filed June 19. 1946 ence to the accompanying drawings.

Patented Sept. 14, 1948 UNITED STATES PATENT OFFICE 2,449,280 pm CASTING MACHINE William Coulthard, Scotby, near Carlisle, England Application June 19, 1946, Serial No. 677,708 In Great Britain June 27, 1945 3 Claims. (01. 22-69)" This invention is for improvements in or relating to die casting, moulding and like machines of the well known kind comprising a die having at least one part which is movable for opening the die, the molten metal or other mouldable material being forced into the die when it is closed by, for example, pneumatic or hydraulic pressure. Heretofore no satisfactory provision has bee made for preventing the opening ofthe die whilst the metal is under pressure (1. e. is being forced into the die), or for preventing the hydraulic or pneumatic pressure, forcing molten metal into the die, being applied whilst the die is open, The result is that there is always a risk of molten metal being squirted from the open or improperly closed die to the danger of the operator.

One object of the present invention is to provide a satisfactory means for preventing the opening of the die when the pneumatic or hyal into the die, is in action and also for preventing such pressure being turned on whilst the die is open.

Accordingly the present invention provides,

application of pressure to the molten metal and also preventing the application of such pressure when the die is open.

In cases where the molten metal is forced into the die by pneumatic or hydraulic pressure; which is the usual arrangement, the present invention may be carried into efiect by providing an interlock arrangement between the valve controlling the hydraulic or pneumatic pressure and the means for opening and closing the die so that the die cannot be opened when said valve is open and furthermore when the die is open the said valve cannot be turned on again until the die has been closed.

One specific embodiment of the invention will now be described by way of example with refer- On the drawings:

Figure 1 is a side elevation of the machine with the die in the closed position,

Figure 2 is a sectional view, to an enlarged scale, on the line II-II of Figure 1,

Figure 3 is a fragmentary side elevation, partly in section showing the die operating mechanism in the open position, and

Figure 4 is a fragmentary perspective view showing the mechanism in the die closing posidraulic pressure operated means, feeding the met- .25 in or for use in, a die casting, moulding or like the die.

2 tion and thefair valve open to cause molten metal to be fed into the die.

Briefly the machine comprises a frame or casing [0 having a fixed support ll for one half I2 of the die and a carriage H! for the other half I4, the carriage being movable to open and close the die on guides l5 mounted on the frame or casing. The, movement of the carriage to open and close the die is effected by a semi-circular crank-like member l6 mounted on a transverse shaft I! provided with an operating handwheel I8. It is preferable to effect the opening and closing of the die by hand means because the closing operation can be felt and thereby carried out in such a manner as to prevent piston of the device I9 is connected by a con necting rod 2| to an arm 22 on the shaft l1.

Thecrank-like member I6 is connected by an adjustable connecting rod 23 to the movable die carriage. One radial edge of the crank-like member is provided with a hard steel abutment 24 adapted to engage an adjustable stop 25, on the frame of the machine, to limit the throw of the crank in the die closing direction (see Figure 4) at a point just beyond its dead-centre position. In this position the crank and connecting rod are best able to take the thrust on the movable part of the die.

An air control valve 26 controlling the pneumatic pressure operating a. plunger mechanism by which the molten metal is forced into the die,

is mounted on the frame of the machine and is provided with an operating hand lever 21. One

provided with bearing plates 30 to take the pressure applied tothe valve operating lever by the movable die part through its operating crank when. the die is closed and metal is being fed into it.

The mechanism above described operates as follows: I

Presuming that the die is open (as shown in Figures 2 and3) the quadrant-like arm. 28 of the valve operating lever 21 lies to one side of the path of movement of the crank-dike member l-B operating the movable die carriage so that this crank is free to move in a vertical plane to close At the same time the valve operating lever 21 and its quadrant-like arm 28 cannot move in a horizontal plane to open the air valve 25 because the path of movement of the quadrant-like? arm 28 is obturated by the' crankr-like member is. In other words ifs an attempt is made to open the air valve 28 such attempt will be frustrated by the quadrant-like arm 28 of the valve operatin lever coming up against one side of the crank-like member It. To clos'e'the die the crank it is moved angularly by its hand. operating wheel i 8, or by operation of the piston and cylinder device it, and this" movement of: the

, position-said. abutment and arm paths in percrank carries it clear of the path of movement'o'f the quadrant-like arm 28 of the air valve lever 27. Once the die has been properly closed it is possible to open the-airvalvaZli andapply pressure to the molten metal and,make .a cast. At the same time it is not possibleto open the die untilth-e air valve 26- has been closed again because the uadrant-likearm 280i the valve operati a lever 27 now obturates the pa'thot movement, in a vertical, plane, of. the-crank-like member iii-as shown in Figure l, Before the die can be opened the: air valve 26 must'bel closed It will be appreciated that the dimensions and length of the pathot movementof. the crank and the quadrant-like arm of the valve operating lever are correlated so that the requiredinterlocks take place attire appropriate times. a

i it In. -a die casting, molding or like machine, wherein: a-fixed-; die portion an-dea movable die portion cooperate to form a die cavity, an oscillatable crank is pivotally mounted on: a support and is connected- With-said movable die portion to eiiect movementithereof relative to said fixed die portion, a valve having a pivotal-stem and controlling means for feeding plastic material to the die cavity is mounted on the support with thezaxis of its valve stem at an angleto the axis of said crank, and a lever i fixed on said valve stem for operatin said valve, the combination with the afore-mentioned elements of an abutment on said crank for movement therewith through a path in the plane in which the-crank moves, and: an 'arm onsa-id leverfor' movement therewith through a path in a planeltransverse the plane of said abutment patlnsa-id crank and said; valve being inounted adjacent eachother on said supportive-position said abutment and arm paths in intersecting relationship, saidcran-k being? mounted on the support to position said abutmentto intercept the arm path when said die is open, and said valve being-mounted on the support to position said arm to intercept'the abutment path when said valve is open; whereby said abutment and said armxar'e selectively movable between positions free of the respective intersecting path and positions transverse the respective intersecting path so that said abutment will; prevent opening of the valve when the die is open" and said arm will reventopening of the die when said valve is open.

2. Ina die casting, molding 'or'like'f machine, wherein a fixed die portion and a movable die portion cooperate to form a die cavity, an oscillatable crank is pivotally mounted on a support and is connected with said movable die portion to effect movement thereof relative to said fixed die portion, a valve having a pivotal stem and.

pendicularly intersecting relationship, said crank being mounted on the support to position said abutment to intercept the arm path when said die is open, and said valve being mounted on the support to position said arm to intercept the abutment path when said valve is open, whereby.

said. abutment and said arm are selectively movable between positions freeof the respectivev in.- tersecting path and positions transverse the. respectiveintersecting path so that said abutment will prevent, openin of the valve when the. die is. open and said arm will prevent opening of the die when said valve is open, and a bearing portion rigid on said support and having a surface slid'ably supporting. said arm in opposition to the direction of the die opening movement of said abutment. j 3 In a die casting, molding or like machine, wherein a fixed die portion and a movable die portion cooperate to form a die cavity, and. oscillatable .crank is pivotally mounted on a support and is connected with said movable die portion to efiect movement thereof relative to-said fixed die portion, a, valve having a pivotal stem and controlling. means for feeding plastic materialto the die cavity is mounted on the support with the axis of its valve stem. at an angle to the axis ofsaid crank,'andl a lever is fixed on said valve stem for operating said valve, the combination with the afore-mentioned elements of an abutment on said crank extending substantially perpendi'cular'to the axis of said crank for. movement therewith through a path in the plane in which the crank moves, an arm on said lever for movement therewith through a path in a, plane perpendicular to the plane of. said. abutment path, a housing in which said. crank is journaled, an opening in said housing, and bearing plates supported by said housing above and below said opening to define a slot in a plane perpendicular to the plane of said crank movement, said valve being mounted on said housing with said arm extending through said slot and slidably supported by said bearing. plates. for movement through a path perpendicular to and intersecting the path of movement of said abutment, whereby said abutment and said. arm areselectively movable between positions free of the respective intersecting path and positions transverse the respective intersecting. path so that said abutment-will prevent opening of the valve when the die is open and said arm will prevent opening of the die when said. valve is open. a

WILLIAM COULTHARD.

' REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,035,956 Furlow Aug. 20, 19-12 1,662,750 Kaufmann Mar. 13, 1928 1,673,832 Lester June 19, 1928 2,173,377 Schultz etal. Sept. 19, 1939 

